Manning's Army supervisor and other officers testify in his court-martial that the young private was an effective intelligence analyst. He is accused of passing secrets to WikiLeaks.

Army Pfc. Bradley Manning is escorted out of a courthouse in Fort Meade,… (Patrick Semansky / Associated…)

FT. MEADE, Md. — Bradley Manning's former Army supervisor described him Wednesday as a highly competent computer whiz who could easily get around secret passwords to retrieve information about enemy terrorist cells.

"He indicated to me he was very fluent in computers, that he spoke their language, and that there was nothing he could not do on a computer," said Jihrleah Showman, a former Army specialist who served as Manning's team leader in Iraq.

Showman testified in Manning's court-martial on charges he aided the enemy by passing thousands of classified documents to the WikiLeaks website. She said the 25-year-old private first class told her he completely "scrubbed" clean his personal computer hardware before applying to join the military, or otherwise he never would have been accepted into the Army.

But beyond painting an often nerdy portrait of a computer expert, Showman said Manning also displayed a much lighter side.

"He talked about social issues," she said. "He talked a lot about liking to attend martini parties in the Washington area and having a lot of friends. And how he loved shopping and, before he joined the military, working as a barista at Starbucks."

He also liked to debate U.S. policy. He was "very political," she said, on the "extreme Democratic side."

Manning is standing trial on 21 charges of illegally downloading and transferring about 700,000 secret reports, videos and State Department cables to the anti-secrecy website WikiLeaks. If convicted, he could be sentenced to life in prison. Earlier this year, he pleaded guilty to 10 lesser charges of mishandling classified information, and for that faces up to20 years behind bars.

He alone has been charged in what became the biggest leak of classified material in U.S. history, sometimes going far afield from his assigned tasks collecting and analyzing intelligence on Iraqi insurgents to retrieve and research secret information about U.S. activities in Iceland, Africa and Europe.

Still, officers who worked with Manning described him as an effective analyst.

Chief Warrant Officer Hondo Hack said Manning was one of the best soldiers who ever worked under him, especially as a junior analyst collecting data on Shiite terrorist groups. "Very neatly organized, very categorized," Hack said. "I've seen a lot of soldiers but not to his level."

And Capt. Casey Fulton said Manning was frequently assigned more work than other analysts. "He was good with computers," she said. "He could get it done quicker."

The scene inside the intelligence collection center at Forward Operating Base Hammer, in the desert east of Baghdad, was described as one in which Manning could have manipulated the secret material largely unnoticed because of many distractions. Showman said soldiers casually listened to music, watched movies and played video games on their computer screens.

Chief Warrant Officer Kyle Balonek, a senior intelligence analyst who also supervised Manning in Iraq, was asked whether music was supposed to be playing on computers. Balonek responded: "It was there, sir. I do not know if it was authorized or not, sir."

Computer video games? "Games were present, yes," he said. "Not at all times, but they were there. And if work was low, it came up."

What Manning was doing, however, was not always monitored.

"He worked with us; he had that level of trust as a co-worker," Balonek said. "You have to trust the other analysts beside you. And it's literally impossible to watch someone 24 hours a day and conduct your own intelligence analysis."

Balonek also read from Manning's government nondisclosure form that he signed, "Manning, Bradley Edward," in September 2008, acknowledging the consequences if he compromised national security information.

Balonek said he told Manning and other soldiers that if "you do this, you lose your clearance immediately and most likely will be arrested."